Originally Posted by Dave Noble

It doesn't matter what availability was at time of booking, what matters is what the availability is at time of making the change

If , at time of making change, there is availability for the standalone flight, then there is no issue making a change

This is not new, this is how married segment availability is designed to work, just that AA seems not to have used it in the past



It is only historical fares that it uses. If making a change after departure, historical fares are used
For availbility, it is only availability at time of making a change that matters